USB Mass Storage is a modus your Android device might present some of its file systems to your computer.
What is USB Mass Storage?
In older Android versions, this was the only method one could access the SDCard of an Android device from a computer via USB cable.
In USB Mass Storage mode (short: UMS), the device grants physical (block-level) access to the storage. Most devices only offer the SDCard in this modus, and for a good reason: Giving block-level access to a different computing device means the storage becoming unavailable locally, to avoid conflicts. For this reason, with newer Android versions the use of MTP (Media Transfer Protocol) is favored (and UMS sometimes even completely disabled): With MTP, the Android device retains complete physical control, only providing logical access to other devices.
Our site holds some other tags related to UMS, which might be used in addition to (or instead of) this tag:
- usb: For generic USB questions. No need to use this additionally, as it is automatically implied.
- usb-connection-mode: This includes UMS as well as MTP and other uses of USB connections, and should e.g. be used if your question is about which connection mode to use.
- usb-host-mode: This is usually the other direction, where your Android device makes use of other USB peripherals. If your question e.g. is about using an external drive attached to your tablet, use this tag instead of usb-mass-storage. Same applies to usb-on-the-go and usb-peripherals.
- usb-storage: Again a generic term, including usb-mass-storage and mtp. If possible, you should use the more specific term -- which leaves this tag for USB drives attached to your Android device in usb-host-mode.
- mtp: As described, newer Android versions prefer the Media Transfer Protocol (MTP). So if your question deals with this, use this tag instead of usb-mass-storage, unless your question deals with both.